How can the number of neutrons in an atom be calculated?

The number of neutrons in an atom can be calculated by identifying the atomic mass and the atomic number of the element. The atomic number indicates the number of protons in the nucleus, while the atomic mass (when rounded to the nearest whole number) provides the total number of protons and neutrons combined.

To find the number of neutrons, you take the rounded atomic mass and subtract the atomic number (which represents the number of protons). This gives you the number of neutrons because the total mass consists of both protons and neutrons, and by removing the number of protons, you are left with just the neutrons.

For example, if an element has an atomic mass of 12 and an atomic number of 6 (which means it has 6 protons), you would calculate the number of neutrons as follows:

12 (rounded atomic mass) - 6 (atomic number) = 6 neutrons.

This method allows you to accurately determine the number of neutrons in any given atom, reflecting its overall nuclear composition. The other methods described in the choices do not yield the correct calculation for neutrons, as they either involve operations that do not pertain to the properties of an atom or mix up the concepts